6-10 day outlook for temperature probabilities for the period from next Tuesday, October 9th to Saturday, October 13th; courtesy NOAA

Overview

Talk about a nation divided…next week’s weather pattern will bring cold and snow to the western US and summer-like warmth to much of the east. Abnormally strong high pressure ridging will set up early next week centered over southeastern Canada and the Northeast US at the same time deep upper-level troughing takes up shop over the Rocky Mountains. As a result, temperatures will soar to the 80’s for highs next week in many parts of the east and will be confined to the 40’s across many sections out west where snow can even pile up in higher elevation locations. In the “battle-zone” region across the middle of the country, expect lots of rainfall over the next week or so.

Upper-level high pressure ridging dominates next week in the eastern US at the same time a deep upper-level trough sets up in the interior western US; courtesy NOAA, tropicaltidbits.com

Eastern US…warmth and a tropical threat for the Gulf region

Very strong high pressure ridging will set up early next week across the northeast US and southeastern part of Canada and this type of weather pattern will have two important ramifications. First, above-normal temperatures are very likely to continue in much of the eastern half of the nation through next week with surface high pressure in firm control. Second, strong high pressure ridging over the Northeast US/SE Canada will open the door for potential tropical activity in the Gulf of Mexico, Caribbean Sea or southwestern Atlantic to ultimately have an impact on the Gulf states from Texas to Florida.

An area of interest in the Caribbean Sea (circled) where there is a tropical wave causing showers and thunderstorms. This system is increasingly likely to spill out over the Gulf of Mexico in coming days and perhaps have an impact on the Southeast US later next week. Meanwhile, Hurricane Leslie is located in the central Atlantic and it should not become a threat to the US.; courtesy NOAA, Wisconsin/CIMMS

In fact, this type of pattern raises a red flag this time of year in the eastern US as tropical systems can “slide underneath” the ridge to the north and head right towards the Southeast US. There is, in fact, a tropical wave right now in the southwestern Caribbean that has to be closely monitored. It is still a bit early to tell for sure, but there is a growing chance that this system spills out over the Gulf of Mexico early next week and it could eventually have an important impact on the Gulf states.

Warmer-than-normal conditions dominate next week in the eastern US at the same time a colder-than-normal weather sets up in the western US; courtesy NOAA, tropicaltidbits.com

Western US…cold and snow

A deep upper-level trough will set up shop next week in the western US likely centered over the Rocky Mountains. Cold air has been generally bottled up in Canada and the Northern Plains in recent weeks, but a change in the upper air pattern to one with an interior western US deep trough will allow for the plunge of Canadian cold air as far south as the Southwest US. In fact, Canada has had substantial snow in some sections in recent days (e.g., Calgary) and has just experienced its coldest September in the satellite era and globally-speaking, it was the coolest September in the last ten years (source).

Snow may pile up next week in some of the higher elevation locations of the western US and Northern Plains; courtesy NOAA, tropicaltidbits.com

In terms of snow, with the plunge in temperatures expected next week in the western half of the nation, some higher elevation locations from the Northern Plains to the Rockies could get several inches of snow. In fact, it is not out of the question that some spots receive a foot or more of snow by the middle of next week and that will likely not be the end of the snow threat.

Coors Field in Denver, Colorado

One final note, the Colorado Rockies will begin a best-of-five playoff series later today with the Milwaukee Brewers in Wisconsin and they will have home games on Sunday and Monday (if needed) in Denver. Given this unfolding “nation-dividing” weather pattern, conditions will not be too baseball-like on either day with temperatures likely confined to the 50’s on Sunday and the 40’s on Monday when there is the possibility for some rain or snow showers.